My nagging oil leak.....

I thought it may be from my oil pan gasket, but that was changed months ago. Same thing with my Intake Manifold, and I did check the head cover gaskets at that time. This last weekend, I did my routine oil change and there was some accumulation on the bottom of my oil pan even before I removed the drainage bolt. I looked at the pan gasket once more and didn't see a leak. Looking on autozone, the only thing that seemed feasible was the front oil seal cover. Can this be it? Never dealing with the above forementioned part, where can I locate this, and how easy would it be to replace?

1994 Lesabre

The only way to find this is to clean everything off and pinpoint the source, or add leak detect dye to the oil as a way to trace the source.